Warning Letter for without intimation Leave.

Dear All,
I am working is new set up Korean MNC company . our employee is absent after Diwali vacation without intimation of 5 days. so may query is that can we given warning letter to him.
Regards,

Dear Ganesh,
The concern employee was joined duty you can give warning letter, if yet to come the duty you can send the RPAL to concern employee address.

Dear Ganesh,
These kind of letters should be sent or issued immediately.
In general a NRD (non-reporting to duty) letter has to be sent on the third day of absenteeism in RPAD (regd post ack due) asking him to explain the reason for absence.
If he comes back even after receiving the letter,hand over a hard copy and take his reply to keep in records which shall make an employee adhere to attendance or leave rules.